There exist a large number of devices which may be used to mix materials. Most such materials are some form of fluid having a suspension of solid particles therein, where the solid particle tend to drop out of suspension, collecting at the bottom of the container, and leaving a substantially liquid material at the top of the container. Paint is a good example of such a material. Prior art mixers for stirring paint to re-suspend the solid particles include everything from a paint paddle, i.e., a flat piece of wood, plastic or metal, which is used to manually stir paint; to complex mixers which are stand-alone devices, and which may receive a container of paint therein and which mix the paint by oscillating actions; to egg-beater type appliances which stir paint with a hook or propeller blade mixing implement. Paint may be supplied in containers sized from one pint to fifty-five gallon containers.
Other materials which need to be mixed prior to use include sauces and salad dressing used in the food industry. Such items are generally delivered to restaurants in five to fifty-five gallon drums.
Concrete may be supplied in dry form in fifty-five gallon drums, which require the mixing of water with the concrete to form a usable product.